(19)
(11) EP 0 455 203 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
27.05.1992 Bulletin 1992/22

(43) Date of publication A2:
06.11.1991 Bulletin 1991/45

(21) Application number: 91106950.8

(22) Date of filing: 29.04.1991
(51) International Patent Classification (IPC)5: H04R 25/02, H04R 1/22, H04R 11/00
(84) Designated Contracting States:
CH DE DK GB LI NL

(30) Priority: 01.05.1990 US 517569

(71) Applicant: KNOWLES ELECTRONICS, INC.
Itasca, Illinois 60143 (US)

(72) Inventor:
  • Carlson, Elmer V.
    Prospect Heights, Illinois 60070 (US)

(74) Representative: Heusler, Wolfgang, Dipl.-Ing. et al
Dr. Dieter von Bezold Dipl.-Ing. Peter Schütz Dipl.-Ing. Wolfgang Heusler Brienner Strasse 52
D-80333 München
D-80333 München (DE)


(56) References cited: : 
   
       


    (54) Dual outlet passage hearing aid transducer


    (57) An improved high-frequency characteristic is achieved, in an otherwise conventional hearing aid receiver transducer by connecting each of the acoustic chambers (41,42) on the two sides of the receiver diaphragm (34), in the receiver housing (29), directly through an outlet port (31,32) and a sound transmission tube (61,62) coupled into the ear canal (64) of the hearing aid user; phase reversals due to resonances in the receiving acoustic chambers and tubes produce a high pass band in the output of the receiver as applied to the user's ear. An acoustically transparent contamination stop (65) prevents contaminants (e.g. cerumen) from reaching the transducer motor (40) but does not interfere with acoustic performance.






    Search report